Manufacture of powdered metals



DEC. 1, 1931. J, H DAVls 1,834,687

MANUFACTURE OF POWDERED METALS Filed DBC. 8, 1927 III] Patented Dec. 1,1931 UNITED STATES PATENT opl-FICE JAMES E. DAVIS, F DAYTON, OHIO,,ASSIGNOR T0 THE HORAIRE PRODUCTS COKPANY, OF DAYTON, OHIO, ACORPORATION 0F OHIO MANUFACTURE 0F POWDERED METALS Application ledDecember 8, 1927. Serial No.,238,591.

This invention relates to a method of and apparatus for manufacturingmetal powders.

The principal object of the invention is to devise an improved method ofmaking metal powder from metal scrap or other forms of metal, and toprovide an improved form of apparatus for carrying out the method, so

as to reduce the cost of manufacture and improve t-he product formed.

In the formation of machine bearings from powdered materials accordingto the method set forth in the patent to H. M. Williams, 1,642,347, amixture of various materials is used, the principal ingredient beingpowdered copper. It is of primary importance in the manufacture ofbearings of the type described in the Williams patent t0 obtain thecopper powder as cheaply as possible, and one oi' the more specificobjects of this invention is to devise a method of and apparatus for themanufacture of copper powder from scrap copper, although the inventionis in no way limited to the production of any particular metal inpowdered form.'

With the above objects in view, a feature of the invention resides inthe method of manufacturing metal powder which consists in forcingmolten metal through a small orifice into an atmosphere of lowertemperature than the metal, directing the metal against a baie andblowing a blast of air through the spray of atomized metal before orafter contact with the baiiie, to further break up the metal.

A further feature of the invention resides in the provision of asuitable apparatus for carrying out the above method.

Further vobjects and advantages of the resent invention will be apparentfrom the 50 force against a movable baille.

ollowing descriptiomreference being had t0' Fig. 3 is a fra entarysectional view of a modified form o apparatus for carrying out theinvention.

l Referring to Fig. 1 of the drawings, the reference numeral 20designates a casing forminga chamber 21 which constitutes a receptaclefor the powdered metal. Integral with and projecting upwardly from thecasing 20 is another casin 22, 1n which is received a vessel 23, whic isadapted to contain molten metal. The casing 22 is provided with a lid 24hinged at 25 which may be opened to lill the vessel 23. A latch bolt 26,pivoted at 27, is adapted to engagefbetween lugs 28 projecting from' the11d and a set screw 29 may be adjusted to hold the latch in latchingposition.

The vessel 23 when in the casing 22 rests on a washer 30 of asbestospacking or other suitable material, positioned in a groove 31, formed inthe bottom of the casing 22 and the up er edge of the vessel engages asimilar pac ing washer 32, positioned around the interior of the casing22 at the top thereof. The lower edge of the washer engages a shoulder83, projecting inwardly from the wall of casing 22 and the top of thewasher projects above the edge of casing 22 in position to be en aged bylid 24, when the latter is closed to orm a tight joint. A pipe 34 leadsto a source of com ressed air.

A hole is provide at the center ofthe bottom wall of the casing 22 andprojecting through said hole into-the chamber 21 is a nozzle 41. Thenozzle is provided with a iange 42 engaging in a corresponding recess 431n the bottom of vessel 23, and a. assage 44 in the nozzle allows metalto flow rom the vessel 23 into chamber 21 when a plug valve 45controlling the passage is open. The valve is provided with a stem 46extendin through a boss on the wall of casing 20 to t e outside of suchcasing where it is provided with a. handle 47 for manual operation ofthe valve.

Situated in chamber 21, immediately below the nozzle 41, is a baille 50against which material issuing from the nozzle 41 will impinge. Thisbaille is in the form of a curved plate projecting from the casing 20 atan angle to the axis of the nozzle, an

is secured 10 to the casing by screws 51. An air blast nozzle 52 isscrewed into the casing 2O below the bale and the tip of the nozz ewithin the casing 21 to a point immediately below the end of the baille50. This nozzle is .adapted to be connected to a' pipe extending to acompressed air supply and the nozzle is so positioned that the blast ofcompressed air from the c amber 21 but prevents the passage of any ofthe metal powder. This screen v may be made of any material having aline enough meshto prevent the passage of the metal particles.

' The above described apparatus operates as follows:

The vessel 23 may be lled with scrap copper or whatever metal it isdesired to convert to powdered form. The lid 24 may then be closed andthe vessel 23 heated to melt the metal therein. The heating means may beof any desired form and, since the heating means forms no part of theinvention, no yparticular form of heating means is disclosed. Instead ofmelting the metal in vessel 23, such metal may be melted elsewhere andpoured into the vessel while in a molten state.

W'hen the vessel 23 is filled with molten metal, compressed air isadmitted through pipe 34 and the valve 45 is opened to allow ow throughthe nozzle 41. The molten metal is discharged at high velocity into theair in chamber 21, which is at considerably 'lower temperature than themolten meta As the molten metal is sprayed from the nozzle it is brokenup into relatively small particles.V The particles of molten metalstrike against the baille 50, the impact acting to break up the metalinto smaller particles than .it is possible to obtain by the atomizingaction of the nozzle alone. In addition to the action of the baie thestream of air at high pressure which is directed by the nozzle 52against the particles as they leave the baffle 50, effects a stillfurther breaking up of the metal powders.

The metal which issues from the nozzle is atomized and more or less inthe form of a spray of molten metal particles.v These particles arestill in a molten state `/when they` strike the baille 50, and while thebaille might be unheated and the air entering the nozzle 52 might becold, it is possible that the particles of molten copper would stick tothe baille to some extent at the beginning of the operation until .thebaille was heated by thel copper itself sulliciently to prevent thisaction. It is accordingly preferable to heat the projects baiiesufficiently to prevent the molten copper particles sticking thereto atany time and better results are obtained when heated air is admittedthrough nozzle 52. The baille ma be heated by any suitable heatingmeans, as iior instance an electric heater, or the baffle may be heatedby the air admitted through nozzle 52 when hot air is employed. The airpassing through the nozzle is directed against the lower end of thebaiile and will heat the baille sufficiently to prevent the molten metalstickin thereto. While other heating means might die employed, thespecific means for heating the balile forms no part of this inventionand no heating means other than nozzle 52, which may be connected to asource of hot air, is disclosed.

The nozzle 41 must also be heated to pre- Y vent the molten metalchilling within the nozzle and stopping the passage therethrough. Thenozzle may be heated by any suitable means such as an electric heater,or if'hot air is admitted through the nozzle 52, such air will heatthednozzle sufliciently to prevent stoppage. Moreover, the nozzle isheated to a considerable degree by Contact with the Crucible. y

Because of the high temperature of molten copper it is necessary thatthe vessel 23 be a Crucible of some suitable refractory material such asgraphite or other rcfractories, while other parts which are inengagement with the metal, such as the nozzle 41, valve 45 and baille50, must be of refractory material also. The modified form of apparatusshown in Fig. 2 is exactly the same as that disclosed in Fig. l with oneexception. The baille and air blast nozzle 52 have been eliminated inthe modified structure and a different device for assisting in theatomization of the molten metal has been provided. In the modifiedapparatus a blower indicated in its entirety by the reference numeral isrotatably mounted immediately below the nozzle 45. The blower is in theform of a hollow drum,` one end of which is secured to a shaft 61journalled in an uprightstandard 62 fixed on the bottom wall of thecasing 20. The opposite endof the drum is provided with'projectingflanges 63 surrounding a central opening into which projects a pipe 64which 'extends through one of the side walls of the casing 20,

' the pi e being secured in said wall by any suitab e means. This pipeserves the double purpose of admitting air from outside of the casing tothe interior of drum 60, and providing a support on which one end of thedrum rotates. The periphery of the drum is provided with fan blades 65which draw air from outside the casing through pipe 64 and force suchair outwardly between the blades as the drum is rotated. A. casing 66entirely surrounds the drum except where the drum projects. through acut-away portion 67 of such casing. .The'casing 66 permits the blow- 21only through er to force air into chamber casing, the cutthe cut-awayportion of the away portion of said casin being so located with respectto the nozzle that the blower 5 forces air through the spray of moltenmetal issuing from the nozzle. The blower may be driven by an electricmotor connected to the shaft 61, or by any other suitable means.

The nozzle 41 and .the blower must be i0 heated suiiiciently to preventchilling of the metal particles, on contact therewith, enough to causethe metal to stick to the nozzle or the blades of the blower. The nozzlean blower may be heated by any suitable means and the admission ofheated air through pip 64 will heat these elements sufficiently effectthe desired result. The pipe 64 may be connected to any convenientsource of hot air..

In the form of the invention disclosed in Fig. 3, a cylinder 70 isformed integral with the casing 20 and projects above said casing 20,occupying the same position relative to the casing 20 as does the part22 of casing 20 in the form of the invention shown in Fig. 1.

The cylinder 70 is lined with refractory material such as graphite orcarborundum as in dicated at 71 and reciprocating within the cylinder isa metal piston 72 havin an outer 80 acket 7 3 of refractory material.passage 4i is provided in one wall of the cylinder to permit filling,with molten metal. A nozzle a 5, of the same construction as the nozzle41, and controlled by a valve 76, similar to valve iso 45, providesmeans of communication be tween the cylinder and the chamber 21.

The piston is reciprocated by an desirable means to force the moltenmetal t rough the nozzle 7 5 when the valve is open and a con- 40ventional means for o erating the piston is shown in Fig. 3. This meanscom rises a cam shaft 80 having a crank pin-81 w ich engages aconnecting rod which is connected to the piston through the usual wristin 83.

The cam shaft is adapted to be driven y any suitable source of power. Asthe piston descends when the valve 7 6 is open, a spra of molten metalis forced throughvthe nozz e in the manner set forth in the description`of the other embodiments of the invention.

Either the baffle and air nozzle 52, or the blower may be employed inthis emh odment of the invention.

While the form of embodiment of the present invention as hereindisclosed, constitutes a referred form, it i's to be understood that oter forms might vbe adopted, all coming within the scope of the claimswhich follow.

What is claimed is as follows:

1. The process of disintegrating metal to form metal powder whichconsists in converting the metal to a molten state, discharging themetal under pressure while molten through a small orifice to effectatomization 05' of the metal, directing the atomiz'ed metal issuing fromthe orifice a-gainsta haine to further disintegrate the metal andforcing a blast of air through the atomized metal to Aalso break up themetal.

2. The process of disintegrating'metal to form metal powder whichconsists in converting the metal to a molten state, discharging themetal while molten through a small orifice to effect atomization of themetal, directing the atomized metal issuing from the orifice against abaffle to further disintegrate the metal and forcing a blast of hot airthrough the atomized metal to also break up the metal.

3. The process of disintegrating metal to form metal powder which c istsin converting the metal to a molten gste, discharging the metal whilemolten through a small vorifice to effect atomization of the metal,directing the atomized metal issuing from. the orifice against a bailleto further disintegrate the metal and forcing a blast of hot air againstthe baille and through the atomized metal, to simultaneously heat .thebaille sufficiently to prevent metal particles sticking thereto and toalso break up the metal particles. 4. Apparatus for disintegrating metalto form metal powder comprisin a crucible adapted to contain molten metaal receiving chamber, adischarge orifice connecting the crucible andreceiving member, means for applying pressure to the molten metal insaid crucible to force the metal through the discharge orifice atsufficient velocit-y to atomize it, and a plurality of means for furtherdisintegrating the metal after the atomized metal issues from thedischarge orifice, said means comprising a baie against which theatomized metal issuing from the discharge orifice is adapted to strikeand means for forcing air under pressure through the atomized metal.

5. Apparatus for disintegrating metal to form metal powder comprising acrucible adapted to contain molten metal, a receiving chamber, a discharorifice connecting the crucible and receivin chamber, means for applyingpressure to t e molten metal in said crucible to force the metal throughthe discharge korifice at suicient velocity to atomize it, a baille insaid receiving chamber against whichthe'atomized metal is adapted tostrike to further disintegrate the metal A and means for heating thedischarge orice ,and bale to prevent metal particles adhering thereto. v

6. Apparatus for disintegrating metal to form metal powder comprisin .acrucible adapted to contain molten meta areceiving chamber, a dischargeorifice connecting the crucible and receiving chamber, means forapplying pressure to the molten metal in said crucible to force themetal through the discharge orifice at sufficient velocity to atomizeit, a bafiie in said receiving chamber against which the atomized metalis adapted to strike to further disintegrate the metal, and means fordirecting hot air under pressure against the baie and through theatomized metal to heat the baffle, and also break up the metal.

b 7. Apparatus for disintegrating metal. to form metal powder comprisinga crucible adapted to contain molten metal, a receiving chamber, adischarge `orifice connecting the Crucible and receivlng chamber, meansfor lo forcing the meta-l through the discharge orifice at sufficientvelocity to atomize it,"'a constantly moving baiiie positioned in thepath of the metal issuing from the nozzle to further break up the metal,and means directing I5 air under pressure through the atomized metal toalsovbreak up said metal.

8. Apparatus for disintegrating metal to form metal powder comprising aCrucible adapted to contain molten metal, a receiving e 20 chamber, adischarge orii'ice connecting the crucible and receiving chamber, meansfor forcing the metal through the discharge orifice at suicient velocityto atomize it, and a rotary blower in the path of the metal ssu- 25 ingfrom the discharge orifice, said blower being provided with fan bladesagainst which the atomized metal is adapted to strike, and means forconnectin the blower to a source of hot air, whereby t e fan blades areheated Re suciently to prevent metal sticking thereto.

ln testimony whereof I hereto aiix my signature.

JAMES H. DAVIS

